Clinical characteristics and outcomes of community-acquired methicillin-resistant Staphylococcus aureus septic arthritis

Objective: We investigated the clinical characteristics, treatment patterns and outcomes of community-acquired methicillin resistant Staphylococcus aureus (CA-MRSA) septic arthritis. Methods: This was a retrospective chart review of CA-MRSA septic arthritis in a tertiary care hospital from 2000-2013. We compared CA-MRSA septic arthritis cases with HA-MRSA septic arthritis cases to identify important differences between the two groups. Results: We identified 11 cases of CA-MRSA septic arthritis and 34 cases of hospitalacquired methicillin-resistant SA (HA-MRSA) septic arthritis. Community-acquired methicillinresistant Staphylococcus aureus caused 25% of the MRSA septic arthritis cases. Communityacquired methicillin-resistant Staphylococcus aureus septic arthritis occurred in younger patients with fewer comorbidities or risk factors. There was no difference in initial presentation between CA-MRSA and HA-MRSA. Community-acquired methicillin-resistant Staphylococcus aureus patients were less likely to be treated with appropriate antibiotics initially. Communityacquired methicillin-resistant Staphylococcus aureus septic arthritis was associated with increased morbidity with a high percentage of patients developing poor joint outcomes or osteomyelitis complications. Community-acquired methicillin-resistant Staphylococcus aureus septic arthritis was also associated with increased utilization of health care resources due to long hospital stays, high readmissions rates, and increased requirements for rehabilitation facility placement and home health support. There was no difference in mortality, poor joint outcome, readmissions, and osteomyelitis complications between CA-MRSA septic arthritis and HA-MRSA septic arthritis. Conclusions: Community-acquired methicillin-resistant Staphylococcus aureus septic arthritis is associated with increased morbidity and health care resource utilization. Increased awareness into CA-MRSA as a cause of septic arthritis in younger patients with no risk factors is important, especially when considering empiric treatment.